Injection molding is a molding technique that can be used for molding small to large objects. A mold can be generated in dedicated injection molding machines comprising a rotating screw in a barrel. The mold can be injected continuously or with a mold buffer by means of pressure.
If the injectable object is large and complicated in shape, the pressure may need to be very high in order to completely fill the cavity. Several hot runners can be used to overcome the high pressure level and to generate an even temperature profile while injecting polyethylene, in order to minimize the warpage of the injected objects.
A material with a desired balance of properties such as stress cracking resistance (FNCT) and impact resistance (Charpy) can be beneficial for injection molding. These properties should be balanced to prevent high warpage of the injection molded article, and may provide a lower injection molding pressure which can be beneficial in the production of large, hollow objects and allowing melt-processing at high values of shear rate without undergoing pressure oscillations and flow-instabilities.